This invention relates to a keyboard musical instrument and, more particularly, to a piano-based musical instrument, a silent system to be incorporated therein and a regulating button mechanism forming a part of the piano-based musical instrument for changing the escape timing depending upon the mode of operation.
A piano-based musical instrument is operative in two modes of operation. One of the modes is selected for playing a piece of music on the keyboard by piano tones, and is hereinbelow referred to as xe2x80x9cacoustic sound modexe2x80x9d. When a pianist wishes to practice fingering on the keyboard without any piano tone, he or she will select the other mode. While the pianist is fingering a piece of music on the keyboard, the hammers rebound before striking the strings, and, accordingly, the strings do not generate the piano tones. If the pianist wants to confirm his or her fingering by electronic tones, the electronic sound generating system specifies the keys depressed and released by the pianist, and generates electronic tones corresponding to the piano tones through a headphone. The other mode is called as xe2x80x9csilent modexe2x80x9d, and the piano-based musical instrument is named xe2x80x9csilent pianoxe2x80x9d.
FIG. 1 shows a typical example of the silent piano. The silent piano is fabricated on the basis of an acoustic piano, and, accordingly, includes a keyboard 1, an action mechanism 2, hammers 3, a damper mechanism (not shown) and strings 4. The action mechanism includes plural action units, which are respectively linked with the black/white keys of the keyboard 1. When a black/white key is depressed, the depressed key actuates the associated action unit, which in turn drives the associated hammer 3 for rotation. The hammer 3 strikes the string 4 so as to give rise to vibrations, and the piano tone is generated through the vibrations of the string 4.
The action unit 2 includes a whippen assembly 2a, a jack 2b and a regulating button 2c. The whippen assembly 2a is connected at one end thereof to a whippen rail 2d by means of a whippen flange 2e, and is rotatable about the whippen flange 2e. The jack 2b is rotatably connected to the other end of the whippen assembly 2a, and has a leg and foot. The foot has a toe 2f and bump 2g, and the toe 2f is opposed to the regulating button 2c. On the other hand, the bump 2g is opposed to an auxiliary regulating button 2h. The regulating button 2c is hung from a regulating rail 2i, which is bolted to a shank flange rail. The shank flange rail is supported by action brackets 2j in such a manner than the regulating button 2c is on the trajectory of the toe 2f. As described hereinbefore, the depressed key actuates the action unit so that the whippen assembly 2a is driven for rotation about the whippen flange 2e. Accordingly, the jack 2b is rotated about the whippen flange 2e together with the whippen assembly 2a, and the toe 2f is getting close to the regulating button. When the toe 2f is brought into contact with the regulating button 2c, the reaction gives rise to rotation of the jack 2b about the whippen assembly 2a. Then, the jack 2b escapes from the hammer 3, and kicks it. This results in the free rotation of the hammer 3. The pianist depresses the black/white key against the total self-weight of the whippen assembly 2a, jack 2b and hammer 3, and feels the black/white key heavy. However, when the jack 2b escapes from the hammer 3, the hammer 3 does not exert any load against the key motion. For this reason, the pianist feels the black/white key light. Thus, the resistance against the key motion is changed at the escape. The change in resistance against the key potion is unique, and is called as xe2x80x9cpiano key touchxe2x80x9d.
The auxiliary regulating button 2h is hung from a shaft 2k, which is rotatably supported by the action brackets 2j by means of bearings 2m. Thus, the auxiliary regulating button 2h is swingable about the centerline of the shaft 2k, and, accordingly, is movable into and out of the trajectory of the bump 2g. The auxiliary regulating button 2h is assumed to be out of the trajectory of the bump 2g. The toe 2g is brought into contact with the regulating button 2c without any interference with the auxiliary regulating button 2h, and the jack 2b turns about the end portion of the whippen assembly 2a due to the reaction from the regulating button 2c. On the other hand, the auxiliary regulating button 2h is assumed to be moved into the trajectory of the bump 2g. The bump 2g is brought into contact with the auxiliary regulating button 2h concurrently with the contact between the toe 2f and the regulating button 2c, and the jack 2b turns about the end portion of the whippen due to the reaction from the auxiliary regulating button 2h. The jack 2b escapes from the hammer 3, and the hammer 3 starts the free rotation. Thus, the bump 2g and the auxiliary regulating button 2h cause the jack 2b to escape from the hammer 3 earlier than that escape therefrom due to the reaction from the regulating button 2c. The regulating buttons 2c, toes 2f, auxiliary regulating button 2h and bump 2g as a whole constitute the prior art regulating button mechanism.
The prior art regulating button mechanism offers two different escape timings to the jack 2b. This is because of the fact that the silent mode requires the early escape timing. In detail, a hammer stopper 5 is provided between the array of hammers 3 and the strings 4. The hammer stopper 5 is changed between a blocking position and a free position. When the hammer stopper 5 is in the free position, the hammer stopper 5 is out of the trajectories of the hammers 3, and strike the strings 4 without any interruption. On the other hand, when the hammer stopper 5 is in the blocking position, the hammer stopper 5 is on the trajectories of the hammers 3, and causes the hammers 3 to rebound thereon before the hammers 3 reach the strings 4. Thus, the hammer stopper 5 permits a pianist to play a piece of music without the piano tones.
When the hammer stopper 5 rests in the free position, the hammer 3 surely starts the free rotation after the escape. However, when the hammer stopper 5 is in the blocking position, the distance between the hammer 3 at the escape point and the hammer stopper 5 is very short. In fact, the distance is of the order of 2 millimeter in a standard grand piano. If action unit 2 causes the jack 2b to escape from the hammer later than usual, the hammer 3 reaches the hammer stopper 5 before completion of the escape, and is pinched between the jack 2b and the hammer stopper 5. The bump 2g and the auxiliary regulating button 2h cause the jack to escape from the hammer 3 earlier. The early escape is equivalent to a wide distance between the hammer 3 at the escape point and the hammer stopper 5. Thus, the bump 2g and the auxiliary regulating button 2h prevent the hammer from the undesirable stick.
Even if the auxiliary regulating button 2h and the bump 2g are removed from the prior art regulating button mechanism, the hammer 3 is prevented from the undesirable stick on the condition that the gap between the toe 2f and the regulating button 2c is decreased. However, the jack 2b escapes from the hammer 3 earlier regardless of the mode of operation. This results in that the pianist feels the key touch unusual.
As will be understood, the silent piano requires the change of escaping timing between the acoustic sound mode and the silent mode, and the bump 2g and the auxiliary regulating button 2h make the silent performance possible. However, a problem is encountered in the prior art silent piano in that prior art regulating button mechanism makes the retrofitting work from an acoustic piano to the silent piano difficult. In detail, users, who have already owned acoustic pianos, wish to retrofit their acoustic pianos to the silent piano. An electronic sound generating system, hammer stopper 5 and auxiliary regulating buttons 2h are added to the acoustic piano, and the standard jacks are replaced with the jacks 2b. Although the assemblage of the electronic sound generating system, hammer stopper 5 and auxiliary regulating buttons 2h is not difficult, the replacement from the standard jacks to the jacks 2b is time consuming, because the worker needs to disassembly the action units and reassemble the parts into the action units, again. The action units are equal in number to the black/white keys. In a standard grand piano, eighty-eight keys form the keyboard 1, and the assembly worker disassembles the eighty-eight action units and reassembles the jacks 2b and other parts into the eighty-eight action units. After the assembling work, the worker regulates the distance between the toes 2f and the regulating buttons 2c and the gaps between the bumps 2g and the auxiliary regulating buttons. Thus, a huge amount of work is required for the retrofitting, and causes the retrofit to the silent piano to be expensive.
The assignee/applicant, Yamaha Corporation, owns the invention disclosed in U.S. patent application No. 09/859, 760, European Patent Application No. 01112256.7, Korean Patent Application No. 10-2001-0027495 and Chinese patent Application No. 01122884.9, which were filed claiming the Convention Priority on the basis of Japanese Patent Application No. 2000-148717. The regulating button mechanism disclosed therein has a regulating bar connected to the change-over mechanism, and the distance between the jack and the regulating bar is regulated by using the adjusting mechanism. The adjusting mechanism projects into the space in front of the action mechanism so that a tuner easily adjusts the distance to appropriate value by using the adjusting mechanism. However, the bump are formed on the foot portion of the jack together with the toe, and the jack escapes from the hammer when either toe or bump is brought into contact with the regulating button or the regulating bar.
It is therefore an important object of the present invention to provide a silent piano, a regulating button mechanism of which cooperates with jacks identical with jacks of an acoustic piano.
It is also an important object of the present invention to provide a silent system, which is installed in an acoustic piano without changing jacks.
It is also an important object of the present invention to provide a regulating button mechanism, in which jacks of an acoustic piano are used as parts of the system.
To accomplish the object, the present invention proposes to make an inner portion of a standard jack brought into contact with a regulating member not later than contact timing between an outer portion of the jack and a regulating button.
In accordance with one aspect of the present invention, there is provided a composite keyboard musical instrument comprising an acoustic piano including a keyboard having plural keys selectively moved by a player positioned in front of the keyboard, plural action units respectively connected to the keys so as to be selectively actuated by the keys moved by the player and having jacks rotatable about axes of rotation, respectively, and a primary regulating member for producing first escapes of the jacks when first portions of the jacks are brought into contact with the primary regulating member, plural beating members respectively driven for rotation by the plural action units when the first escapes or second escapes are produced, plural vibratory members respectively struck with the plural beating members at the end of the rotation, and an auxiliary regulating button sub-mechanism including a secondary regulating member moved into the trajectories of the jacks and permitting second portions of the jacks closer to the axes of rotation than the first portions to be brought into contact therewith for the second escapes at certain timing not later than the contact between the first portions and the primary regulating member and a change-over mechanism connected to the secondary regulating member so as to move the secondary regulating member into and out of the trajectories of the jacks.
In accordance with another aspect of the present invention, there is provided a silent system installed in an acoustic piano for retrofitting the acoustic piano to a composite keyboard musical instrument comprising an auxiliary regulating button mechanism associated with an action mechanism of the acoustic piano and including a regulating member movable into trajectories of jacks of the acoustic piano and permitting inner portions of the jacks closer to axes of rotation for the jacks than outer portions of the jacks to be brought into contact therewith at a certain timing not later than the contact between the outer portions and regulating buttons of the acoustic piano and a change-over mechanism connected to the regulating member so as to move the regulating member into and out of the trajectories of the jacks, a hammer stopper associated with hammers of the acoustic piano, and changed between a free position out of trajectories of the hammer and an interference position on the trajectories of the hammers so as to cause the hammers to rebound thereon, and an electronic sound generating system associated with at least keys of the acoustic piano, and generating electronic tones corresponding to piano tones to be generated by depressing the keys.
In accordance with yet another aspect of the present invention, there is provided an auxiliary regulating button mechanism for accelerating escape of jacks forming a part of an action mechanism incorporated in an acoustic piano comprising a regulating member supported by a stationary member of the acoustic piano, and causing the jacks to escape from hammers of the acoustic piano when certain portions of the jacks are brought into contact therewith, the certain portions being closer to axes of rotations for the jacks than portions of the jacks to be brought into contact with regulating buttons of the action mechanism, and a change-over mechanism connected to the regulating member, and changing the regulating member between a first position out of the trajectories of the certain portions and a second position where the certain portions are brought into contact with the regulating member at a certain timing not later than a contact timing at which the portions are brought into contact with the regulating buttons.